A typical aircraft includes a large number of components such as hydraulic line and valves. These components are vital to the proper operation of an aircraft and may be responsible for items such as control systems, supply of power, and actuation of various items. In an effort to improve the safety of an aircraft, there is currently a push to ensuring these components will continue to operate in adverse conditions, such as a fire. For example, FIG. 1 illustrates an example of a check valve 10 for use in an aircraft hydraulic system. Ideally, the check valve 10 should continue operating if exposed to hot gases, such as a fire.
Current techniques for protecting a component are inadequate for the extreme conditions that an aircraft component may be subject to. For example, in the event of a fire a component may be subject to extreme temperature caused by the combustion of jet fuel, or may encounter corrosive fluids such as hydraulic fluid. Furthermore, it is essential that any modification of a component to protect against these conditions be simple to use and not impact the overall weight of the aircraft significantly.
One traditional method of insulating a component is to wrap the component in a blanket of insulating fibers such as mineral wool. While effective against heat in general, a blanket of mineral wool tends to absorb oil which may lead to degradation or ignition of the oil when heated.
Another method for insulating a component has been to place a heat shield such as a hard shell between the heat source and the component being protected. Heat shields, however, are typically conductive and leave too much air volume between the shield and component. This air may superheat and heat the component through convection.
A combination of these two methods is to use a heat blanket and covered fibrous insulation. This solution, however, is not very elegant and is difficult to install properly. If not installed properly, the effectiveness of this solution diminishes.
In view of the preceding, it would be beneficial to develop insulation for components of an aircraft that resists high temperatures and corrosive fluids and that is not excessive in weight or volume. Ideally such insulation would be easy to apply such that its effectiveness was not dependent upon the installer's level of skill.